Additives for paper

ABSTRACT

Additives used for increasing the retention of fibers and fillers in the production of paper and in the treatment of sewage, the additives being copolymers of 85-95 % by weight of Mannichbases of (meth)acrylamide carrying at least one hydroxyalkyl group or being derived from heterocyclic sec. amines and 15-5 % by weight of tertiary or quaternary aminoalkyl(meth)acrylates.

United States Patent 1191 Sackmann et al.

[ Sept. 23, 1975 I ADDITIVES FOR PAPER [75] Inventors: Gijnter Sackmann,Opladen; Giinter Kolb, Leverkusen; Friedhelm Miiller, Odenthal, all ofGermany [73] Assignee: Bayer Aktiengesellschaft, Germany 22 Filed: Sept.9, 1974 [21] Appl. No.: 504,558

[30] Foreign Application Priority Data Sept. 12, 1973 Germany 2345922[52] US. Cl. 260/793 MU; 162/168; 260/861 R; 260/861 E; 260/861 N [51]Int. Cl}... C08F 220/00; C08G75/00; D21D 2,862,893 l2/l958 I-Iwa..260/79.3 MU

3,323,979 6/1967 Foster et al 162/167 3.410649 11/1968 $61161 3,700,63510/1972 Brust et al. 1. 260/793 MU 3,758,445 9/1973 Cohen et al. 260/861N 3.842054 10/1974 Keim 260/861 N OTHER PUBLICATIONS Schiller et 211.,Industrial and Engineering Chemistry, Vol. 48, N0. l2, December I956,pp. 2l322l37.

Primary ExaminerRonald W. Griffin Attorney, Agent, or FirmConn0lly andI-Iutz [57] ABSTRACT Additives used for increasing the retention offibers and fillers in the production of paper and in the trezitment ofsewage, the additives being copolymers of 85-95 7r by weight ofMannichbases of (meth)acrylamide carrying at least one hydroxyalkylgroup or being derived from heterocyclic sec. amines and l5-5 by weightof tertiary 0r quaternary aminoalkyl(meth)acrylates.

1 Claim, N0 Drawings ADDITIVES FOR PAPER This invention relates toadditives used for increasing the retention of fibers and fillers bothin the production of paper and in the treatment of sewage, the additivebeing based on copolymers of special Mannich bases of (meth) acrylamideand tertiary or quaternary aminoalkyl (meth) acrylates.

It is known that water-soluble polymers based on poly( meth) acrylamidecan be used for increasing the retention of fibers and fillers in theproduction of paper.

According to one of our own earlier proposals (cf. GermanOffenlegungsschrift No. 2,255,391), this effeet can be improved by usinghigh molecular weight cationic copolymers of (meth) acrylamide andtertiary or quaternary aminoalkyl (meth) acrylates copolymerized in from1 to less than 10% by weight aqueous solutions in the presence of from0.005 to 0.1% by weight a Redox system of a water-soluble percompoundand from 0.005 to 0.1% by weight of a compound containing at least oneprimary amino group or its watersoluble salt all the percentages beingbased on the total monomer used, and optionally in the presence of atmost 10% by weight of a water-soluble metal salt, based on the sum ofwater and metal salt, at a temperature in the range from 10 to 40C.

It is also known that polymeric Mannich bases can be obtained byreacting homopolymers or copolymers of acrylamide with formaldehyde andprimary or secondary amines (Schiller and Suen, 1nd. and Engng. Chem. 481956) 2132). The use of products of this kind, prepared using dimethylor diethyl amine as the secondary amine, as dehydrating additives isalready described in U.S. Pat. No. 3,323,979. Although products of thiskind shown improved dehydrating properties compared with unmodifiedpolymers, they also have unfavourable physiological properties and inuse smell strongly on account of the fact that only amines of lowboiling point are used. If, however, amines having a higher boilingpoint are used to overcome this disadvantage, the solubility of theseproducts in water is adversely affected, with the result that it isextremely difficult, if not impossible, to dilute them to the extremelylow concentration required for the production of paper. In addition,they are far less active as retention agents.

It has now surprisingly been found that water soluble amines of arelatively high boiling point can be also used providing they contain atleast one hydrophilic functional group, for example a hydroxyl group, orproviding they are isocyclic or heterocyclic in character. Compared withconventional products, these products ;show an improved retentioncapacity, a comparatively lower viscosity in aqueous solutions for thesame concentration, a greater affinity for dilution with water andimproved physiological properties.

Since solutions of Mannich bases of this kind, due to -their production,still contain free amines in equilibrium, the question of biologicaldegradability is important. Investigations have shown that aliphaticamines having hydroxyl groups are more readily degraded in sewage thanamines without those groups. Thus, monoethanolamine undergoes 60%degradation after 20 days (C. 8. Lamb and G. F. Jenkins BOD of syntheticJr: BOD of organic chemicals: Sewage 1nd. Wastes 28 (1957) 1267-4272);in the case of cetytrimethyl ammonium bromide, the degradation rateafter 5 days amounts to 0% (W. Winter: Biodegradation of detergents insewage treatment, Wasserwirtsch Wassertech 12 (1962) 265-271).

Accordingly, the invention relates to an additive for increasing theretention of fibers and fillers in the production of paper or in thetreatment of sewage which is based on a copolymer consisting essentiallyof a. to by weight of statistically distributed polymeric units ofMannich bases corresponding to the formula in which R representshydrogen or methyl;

R represents a hydroxy alkyl group with 2 or 3 carbon atoms;

R represents an alkyl group with 1 or 2 carbon atoms;

R, and R each represent a hydroxy alkyl group with 2 or 3 carbon atomsor R, and R together with the N-atom to which they are attachedrepresent a pyrrolidine, morpholine, N-methylpiperazine orN-ethylpiperazine ring, and

b. 15 to 5% by weight of statistically distributed polymer units ofaminoalkyl (meth) acrylates corresponding to the formula Rs X() in whichR represents hydrogen or methyl;

A represents an alkylene radical with from 2 to 4 carbon atoms;

R represents hydrogen or alkyl with from 1 to 4 carbon atoms;

R, and R represent alkyl with 1 to 4 carbon atoms and X" represents anegative group capable of salt formation with the amide nitrogen, suchas halide, acetate, methosulphate or tolylsulphate.

in formula 11 above, R is preferably hydrogen or methyl, A is preferablyan ethylene group, R is preferably hydrogen, R, and R are preferably amethyl or ethyl group and X" is preferably chloride.

The copolymers of (meth) acrylamide and salts of i tertiary orquaternary aminoalkyl (meth) acrylates are prepared in oxygen-freeaqueous solution, the monomers being copolymerized in the form of from 1to less than by weight aqueous solutions in the presence of a redoxsystem of from 0.005 to 0.1% by weight of water-soluble percompounds andfrom 0.005 to 0.1% by weight of a compound containing at least oneprimary amino group or water-soluble salt thereof based on the totalmonomer used, and optionally in the presence of at most 10% by weight ofa water-soluble metal salt, based on the sum of water and metal salt, ata temperature in the range from 10 to 40C.

The monomer is acrylamide and /or methacrylamide, preferably acrylamide.

Preferred aminoalkyl(meth)acrylates are dimethylaminoethylacrylate,dimethylaminoethylmethacrylate, diethylaminoethylacrylate,diethylaminoethylmethacrylate, or the hydrochlorides of these compounds.

(Meth)acrylamide and an aminoester together are used in the form of from1 to less than 10% by weight, preferably in the form of from 2 to 6% byweight, aqueous solutions for copolymerization.

The monomer mixture used consists of from 80 to 95% by weight of(meth)acrylamide and of from 5 to by weight of the aminoester.

The monomers are present in the copolymer in substantially the initialratio. If they are present in a quantity of less than 5% by weight, themonomers show inadequate cation activity, while when they are present inquantities of above 30% by weight the products obtained have extremelyhigh molecular weights.

The monomer units are incorporated into the copolymers in asubstantially statistical distribution.

The copolymers procuced have intrinsic viscosities [n] of from 12 to(dl/g), as measured in a 0.9% by weight NaCl solution at t 25C.

The aqueous copolymer solutions obtained contain from 1 to 10% byweight, preferably from 2 to 6% by weight, ofsolid copolymer and haveviscosities of from 6000 to 80,000 cP, preferably from 10,000 to 40,000cP, at t 20C.

The polymerization initiators used are redox systems containing, astheir oxidizing component, water-soluble compounds, such as alkali metalor ammonium persulphate, hydrogen peroxide, tertiary butylhydroperoxide, or percarbonates and perphosphates. The reducingcomponents of the redox systems are compounds which are soluble in wateror are salts of these compounds and contain at least one primary aminogroup, such as diethylenetriamine, triethylenetetramine, me-

thylamine, n-butylamine, isobutylamine, cyclohexyl- Copolymerization mayoptionally be carried out in the presence of water-soluble metal salts,such as sodium chloride, sodium sulphate, magnesium chloride, aluminiumsulphate or sodium acetate. These simple electrolytes can be present inthe polymerization mixture in quantities of up to 10% by weight, basedon the sum of water and water-soluble metal salt.

The Mannich bases are preferably prepared in known manner by reactingthe polymers which contain amide groups in aqueous solution with anaminomethylation reagent which is obtained by reacting the particularamine or mixtures thereof with formaldehyde, at room temperature in thepresence or absence of catalysts. Examples of suitable amines include2-methylamino ethanol, 2-ethylaminoethanol, l-methylamino-2- propanol,l-methylamino-3-propanol, 2-methylaminol -propanol, l-ethylamino-2-propanol, lethylamino-3-propanol,Z-ethylam'ino-l-propanol, diethanolamine, morpholine, pyrrolidine,N-methylpiperazine and N-ethylpiperazine or mixtures thereof. 2-Methylaminoethanol, l-methylamino-2-propanol, diethanolamine,morpholine, pyrrolidine or N-methylpiperazine, or mixtures thereof, arepreferably used.

The molar ratio of amine to formaldehyde is between 1:1 and 5:1,preferably amounting to 2:1. Copolymer solutions containing from 1 to10% by weight and preferably from 2 to 6% by weight of solid copolymercan be used as the copolymer solutions. The Mannich base solutions thusformed have viscosities of from 1500 to 60,000 cP, preferably from 2000to 8000 cP, at t 25C.

Reaction of the copolymer containing amide groups to form the Mannichbase may optionally be carried out in the presence of a water-solublemetal salt, such as sodium chloride, sodium sulphate, magnesiumchloride, aluminium sulphate or sodium acetate.

These simple electrolytes can be present in the polymerization mixturein quantities of up to 10% by weight, based on the sum of water andwater-soluble metal salt.

However, it is also possible to prepare the paper additives of theinvention by copolymerizing the monomeric Mannich bases of(meth)acrylamide and the tertiary or quaternary aminoalkyl(meth)acrylates. The Mannich bases can be prepared in known manner fromthe methylol ethers or the free methylol compounds and the requiredsecondary amines, or from (meth) acrylamide, formaldehyde and therequired secondary amines.

The products obtained in accordance with the invention can be used inthe paper industry and in the purification and treatment of sewage.irrespective of pH, but especially in the neutral and acid range theyprovide a high level of retention of fibers and fillers on thepapermachine wire in the production of paper, and accelerate the removalof water from the paper web without affecting anionic opticalbrighteners to any appreciable rectly added to the breast box ofpaper-making ma- I chines in diluted or undiluted form. In addition tothis application, the products according to the invention can also beused in'the treatment and purification of industrial and municipalsewage by sedimentation, filtration and flotation, their favourablephysiological behaviour and their high biological degradability beingparticularly advantageous in this respect.

The percentage contents quoted in the following Examples relate toweight unless otherwise stated. Production of a starting material fromacrylamide/diethylamino ethylrnethacrylate hydrochloride copolymer:

170 liters of desalted water are introduced into a 250 liter capacitysteel autoclave equipped with a stirrer and surmounted by a distillationbridge. The autoclave is then heated to 80C and 12 liters of waterdistilled off under vacuum. 2 atms of pure nitrogen are then introducedinto the autoclave and it is cooled to 25C. A so- EXAMPLE 1 A paper wasproduced in a test paper-making machine (Kammerer system) from a pulpconsisting of 70% of bleached softwood sulphite cellulose and 30% ofbleached hardwood sulphate cellulose ground to 40 on theSchopper-Riegler scale at pH 4.8. in the presence of 25% china clay, 1%resin size (Na-abietate) and 3% aluminium sulphate (the percentages ineach case based on dry cellulose). Heavily water-diluted solutions(approximately 0.05% by weight) of the retention agents described abovewere continuously added just before the breast box of the machine. Theretention effect was determined by measuring the solids content of theeffluent of the paper-making machine.

of 7200 g of acrylamlde and 9 g of ilethyl The results are set out inthe following Table, the ammo ethylmethacrylate hydrochloride in 9.4hters of quantities added being expressed as 100% products, boiled,desalted water are then sucked mto the autobased on dry cellulose. clavethrough a capillary. Thereafter, a vigorous stream of nitrogen is blownthrough the solution for about one hour, and the autoclave is closed.1.20 g of aminoethyl- Retention Solid content or effluent for the tdd't' r methacrylate hydrochloride (amine component of the 0.00% 00022963 362 8% 0.007295 redox system), dissolved in 2.16 liters of boiled,demg mg mg" mg" slated water, are then quickly introduced through adropping funnel while nitrogen is passed over, the reac-' g 'gafil z 530297 234 tion mixture followed by the dropwise addition of 2.40amideldielhyl g of potassium persulphate, dissolved in 2.52 liters of i'g'rgg g f ig boiled, desalted water, over a period of 1 hour. On 5 p y530 267 [82 U8 completion of the dropwise addition, the autoclave is 6530 222 164 127 2 530 234 156 134 closed and nitrogen lS introducedunder a pressure of 2 atms. After a reaction time of 24 hours at 25 toC, 30 a crystal-clear highly viscous solution (32,000 cP at t 20C) isformed and can be forced out of the reaction COMPARISON EXAMPLE 1 Vessely FPP an execs? Pressure A polymeric Mannich base obtained by reacting ia polyacrylamlde thus Prepared has an P polyacrylamide with formaldehydeand dimethylamine g N g ly 1] of -;5 h as mleasured was used for thiscomparison example. lnvestigation 0 a "tion at t o e P ymel' showed thatits retention effect, determined under the sists of copolymerized,substantially statistically distribsame conditions as in Example 1 wasbetter than that units, of axlliproldmatel)"% y Weight of acrylam' ofthe unmodified copolymer and slightly poorer then ide and 20% y weightof dlethylammoethyl methacry' that of the Mannich bases mentioned inExample 1. 1n lat hy rochl ri addition to its already mentioneddisadvantages, of PREPARATlON OF THE RETENTEON AG ENT poor degradabilityand strong smell, the product has g of a 30% aque us formald hy l i n rthe further disadvantage of a very low affinity for diluad ed dropwiseat f f a Solution 9 2 each tion to the low concentrations required inthe producof the amines specified n the followmg Table in a 1 45 on ofpaper, liter 3-necked flask equipped with a stirrer, internalthermometer and reflux condenser. The quantity of water is selected insuch a way that l g of the end solution contains 0.056 g offormaldehyde. 523 253 g g M 182 g of these solutions are stirred with500 g of a 6% g 000% mom, .43 0,0072% aqueous solution of a copolymer of80% by weight of 50 mg/l s/ a Ins/l acrylamide and 20% by weight ofdimethylaminoethylpolyacrylamide methacrylate hydrochlorlde, 30 g ofsodium chloride Mannich base or and 288 ml of water in astirrer-equipped vessel until f i and 530 228 dimethylamme ahomogeneous, crystal-clear mixture [8 obtained.

Concentration of Viscosity Composition of the solution of of the theretention agent the retention agent.

retention Retention polymeric units of based on starting agent at AgentAmine Mannich bases eopolynier t 25C.

I Z-methylamino 90.0% by 2.0% by 2600 cl ethanol weight weight 3l-methylamino- 10.7% by 3.0% by 5400 eP Z-propanol weight weight 3diethanolamine 91.8% by l.2.2 by 4300 CP weight weight 4 inorpholine90.7% by 3.0% by (1000 cf weight weight 5 pyrrolidine 89.7% by 2.5% by3100 cP weight weight 6 N-methyl '9l.3'/1 by 2.5% by 2000 eP piperalineweight weight difference between the respective percentages and 100 J byweight of inninoester in retention agent EXAMPLE 2 The test was carriedout and the test results evaluated in the same way as described inExample 1-.

Retention Solids content of effluent for agent additions of mg/l mg/lmg/l mg/l Unmodified copolymer (cf. 610 386 243 193 Example 1) l 6l0 267l92 I40 EXAMPLE 3 The test was carried out and the test resultsevaluated in the same way as Example 1 and 2.

1. Additives useful for increasing the retention of tibers and fillersin the production of paper or in the treatment of sewage comprisingcopolymers consisting essentially of 85 to 95% by weight ofstatistically distributed polymeric units of Mannich bases correspondingto the formula:

wherein R is hydrogen or methyl;

R is hydroxyalkyl having 2 to 3 carbon atoms;

R is alkyl having I to 2 carbon atoms;

R and R are each hydroxyalkyl having 2 to 3 carbon atoms;

R and R together with the nitrogen atom to which they are attached arepyrrolidino, morpholino, N- methylpiperazino or N-ethylpiperazino and 15to 5% by weight of statistically distributed polymeric units of thefomula:

wherein R is hydrogen or methyl;

A is alkylene having 2 to 4 carbon atoms;

R, is hydrogen or alkyl having 1 to 4 carbon atoms;

R, and R are alkyl having I to 4 carbon atoms X is a negative groupcapable of salt formation with the amine nitrogen selected from thegroup consisting of halide, acetate, methosulphate and tolylsulphate.

1. ADDITIVES USEFUL FOR INCREASING THE RETENTION OF FIBERS AND FILLERS IN THE PRODUCTION OF PAPER OR IN THE TREATMET OF SEWAGE COMPRISING COPOLYMES CONSISTING ESSENTIALLY OF 85 TO 95% BY WEIGHT OF STATISTICALLY DISTRIBUTED POLYMERIC UNITS OF MANNICH BASES CORRESPONDING TO THE FORMULA: -CH2-C(-R)(-CO-NH-CH2-N(-R1)-R2)WHEREIN R IS HYDROGEN OR METHYL, R1 IS HYDROXYALKYL HAVING 2 TO 3 CARBON ATOMS, R2 IS AKYL HAVING 1 TO 2 CARBON ATOMS, R1 AND R2 ARE EACH HYDROXYALKYL HAVING 2 TO 3 CARBON ATOMS, R1 AND R2 TOGETHER WITH THE NITROGEN ATOM TO WHICH THEY ARE ATTACHED ARE PYRROLIDIONE, MORPHOLINO, N-METHYLPIPERAZINO OR N-ETHYLPIPERAZINO AND 15 TO 5% BY WEIGHT OF SATISTICALLY DISTRIBUTED POLYMERIC UNITS OF THE FORMULA: -CH-C(-R)(-COO-A-N(+)(-R3)(-R4)-R5)- X(-) WHEREIN R IS HYDROGEN OR METHYL, A IS ALKYLENE HAVING 2 TO 4 CARBON ATOMS, R3 IS HYDROGEN OR ALKYL HAVING 1 TO 4 CARBON ATOMS, R4 AND R5 ARE ALKYL HAVING 1 TO 4 CARBON ATOMS X(-) IS A NEGATIVE GROUP CAPABLE OF SALT FORMATION WITH THE AMINE NITROGEN SELECTED FROM THE GROUP CONSISTING OF HALIDE, ACETATE, METHOSULPHATE AND TOLYLSUPHATE. 